1. Field of the Invention
The present invention relates to a weft inserting control device for a fluid jet type loom for controlling weft reaching timing with relation to a rotation phase of a main shaft of the loom in weft insertion in the fluid jet type loom.
2. Description of the Related Art
Hitherto, in order to converge a dispersion of weft insertion completed timing for a rotation phase of a main shaft of a loom (referred to as weft reaching angle, hereinafter) at a predetermined weft reaching angle, an average deviation, which is an average of difference between an actual reaching angle and an objective reaching angle of weft yarn, has been calculated for every predetermined number of weft insertion times (referred to as picking number, hereinafter). It is arranged that, when the average deviation passes over a predetermined allowable range, fluid jet pressure of a main nozzle or an auxiliary nozzle for weft-inserting be controlled so that the reaching angle would be within the allowable range.
There is also proposed a method for measuring weft inserting power for each weft insertion to accumulate a difference between the weft inserting power and a reference value, and then, controlling the pressure of fluid supplied to a weft inserting nozzle or the rotating number of the main shaft of a loom when the accumulated value passes over an allowable range, as disclosed in a bulletin of Japanese Patent Publication No.39735/1994.
In the case of the former related art described above, however, it is difficult to determine a certain picking number for calculating the average deviation. Excessively large picking number leads to bad response for a rapid change of a weft reaching angle in changing supplied weft where a sort of weft is changed, which sometimes causes a unit to be out of control and stopped. On the contrary, excessively small picking number for calculating the average deviation leads to oversensitive response of a controlling system for a temporary rapid change of the weft reaching time even when the weft reaching angle is almost stable within the reference value, so that the pressure of a weft inserting nozzle would be changed and the reaching angle would not be stable in a converging direction to the contrary, which sometimes causes large dispersion of the reaching angle.
In the case of the latter related art described above, the response for a rapid change of the weft reaching angle can be better in controlling than the former related art described above. It is also difficult, however, as well as the above to determine an allowable range of the accumulated value. Excessively wide allowable range leads to inferior response in controlling similarly to the above, while excessively narrow allowable range leads to oversensitive response also for insignificant deviation of the reaching angle, both of which cause a problem that the reaching angle of weft is not stable. Thus, there have been problems of response and stability in controlling, which are conflicting each other, remaining.
In view of the above-described problems of the related art, the invention has been made and is aimed to provide a weft inserting control device for a fluid jet type loom in which the response in controlling weft insertion can be improved and whose weft reaching angle can be stabilized, with a simple structure.
The invention provides a weft inserting control device for a fluid jet type loom comprising: a weft insertion detecting unit for detecting dispersion of a weft reaching angle in a plurality of control cycles; and a controlling unit for comparing a plurality of detection values of the weft reaching angle given by the weft insertion detecting unit with a plurality of respective different reference values, and for controlling the weft reaching angle based on a result of the comparison in every control cycle.
The reference values are set so as to have a minus correlation with a length of the respective control cycles. And the detection value is at least one deviation from the reference values of the weft reaching angle in the respective control cycles or is an average value of the deviation.
The controlling unit for the weft reaching angle controls supplied fluid pressure of the weft inserting nozzle, the timing of weft insertion, the rotation number of a main shaft of a loom or such in accordance with fuzzy reasoning corresponding to the above detection value. The weft reaching angle is controlled on the basis of the detection value in the shorter control cycle among the control cycles in which the detection value over the reference value is obtained, when the detection value in a plurality of control cycles is respectively over the reference value. dr
FIG. 1 is a schematic view of a weft inserting control device for fluid jet type loom according to the first embodiment of the invention;
FIG. 2 is a flowchart showing a controlling method of the weft inserting control device according to the embodiment of the invention;
FIG. 3 is a flowchart showing a method for controlling nozzle pressure and continued from the flowchart shown in FIG. 2;
FIG. 4 is a graph showing a controlling method of the weft inserting control device according to the embodiment of the invention;
FIG. 5 is another graph showing a controlling method of the weft inserting control device according to the embodiment of the invention;
FIG. 6 is a flowchart showing a controlling method of the weft inserting control device according to the second embodiment of the invention;
FIG. 7 is a flowchart showing a controlling method of the weft inserting control device according to the third embodiment of the invention; and
FIG. 8 is a flowchart showing a controlling method of the weft inserting control device according to the fourth embodiment of the invention.